Identification and Analysis of microRNAs in Chlorella sorokiniana Using High-Throughput Sequencing

Abstract

Chlorella is a popular microalga with robust physiological and biochemical characteristics, which can be cultured under various conditions. The exploration of the small RNA content of Chlorella could improve strategies for the enhancement of metabolite production from this microalga. In this study, stress was introduced to the Chlorella sorokiniana culture to produce high-value metabolites such as carotenoids and phenolic content. The small RNA transcriptome of C. sorokiniana was sequenced, focusing on microRNA (miRNA) content. From the analysis, 98 miRNAs were identified in cultures subjected to normal and stress conditions. The functional analysis result showed that the miRNA targets found were most often involved in the biosynthesis of secondary metabolites, followed by protein metabolism, cell cycle, and porphyrin and chlorophyll metabolism. Furthermore, the biosynthesis of secondary metabolites such as carotenoids, terpenoids, and lipids was found mostly in stress conditions. These results may help to improve our understanding of regulatory mechanisms of miRNA in the biological and metabolic process of Chlorella species. It is important and timely to determine the true potential of this microalga species and to support the potential for genetic engineering of microalgae as they receive increasing focus for their development as an alternative source of biofuel, food, and health supplements.

Enhanced nitrogen removal via Yarrowia lipolytica-mediated nitrogen and related metabolism of Chlorella pyrenoidosa from wastewater

“…miRNAs can regulate gene expression through destabilization of the mRNA and translational repression ( Chung et al, 2017 ). Most miRNAs are involved in regulating the biosynthesis of secondary metabolites, followed by protein metabolism ( Azaman et al, 2020 ). From the above results, it can be seen that the transcription level of genes related to amino acid synthesis in C. pyrenoidesa is regulated by miRNAs, and miRNAs have a certain influence on nitrogen entering C. pyrenoidesa to synthesize amino acids.…”

“…MicroRNAs (miRNAs) are key regulators in gene expression that can control gene expression via messenger RNA (mRNA) cleavage or translational repression ( Djami-Tchatchou et al, 2017 ; Lou et al, 2018 ). Meanwhile, miRNA-target genes are primarily involved in secondary metabolite biosynthesis ( Azaman et al, 2020 ). Microalgae nitrogen metabolism can be influenced by both miRNA and mRNA, and the presence of yeast stimulates gene expression in microalgae.…”

MicroRNA Expression Profile Analysis of Chlamydomonas reinhardtii during Lipid Accumulation Process under Nitrogen Deprivation Stresses

“…Recently, the investigation of algae miRNAs has gained more attention due to their vital function in metabolic processes and adaptation to various stresses. Currently, different algae miRNAs genes, including Chlamydomonas reinhardtii [ 43 , 44 , 45 ], Chlorella sorokiniana [ 46 ], and Botryococcus braunii [ 47 ], have been identified, and some of them also have been well characterized. However, the role of miRNAs in lipid accumulation under nitrogen deprivation stress for microalgae is still unclear.…”

Circulating exosome miRNAs, is it the connection cargo for cell communication and cross-kingdom communication by food chain in bivalves?

“…Recently, some studies focused on microalga miRNAs and their potential functions. Azaman et al identified miRNAs from Chlorellasorokiniana , and 98 miRNAs were identified in cultured microalgae subjected to normal and stress conditions (Azaman et al, 2020). Deng et al found that miRNAs inBotryococus braunii were involved in metabolic and cellular processes, gene expression regulation, and stress/defense functions (Deng et al 2017).…”